1. Field of the Invention
The present invention relates to electrical sockets and connectors in general, and more particularly to a female holder or socket for a compact fluorescent lamp having two or more compact fluorescent tubes which share a common base, wherein the socket provides electrical connections and gripping means for the lamp base.
2. Description of the Related Art
Compact, super compact or "Mini-" fluorescent lamps, known by many commercial names, such as Philips "PL" and "PLC", OSRAM "DULUX S", "DULUX D" and "DULUX E", Sylvania "Twin Tube" and "DBL Twin Tube" and GE "Mod-U-Line", are rapidly gaining in popularity because they often provide as much light as a similar size incandescent lamp while requiring less than one-third the power and achieving 10 times greater service life.
These compact fluorescent lamps require a range of sockets of unique design, in order to provide advantages to the user which may include various mounting methods to a surface, keying to accept lamps of correct wattage and rapid, safe and easy wiring. Employing all the advantages are important with this type of lamp, because with all connections made at a single base rather than at opposite ends of the common fluorescent tube, compact fluorescent lamps are finding application in space-saving lighting fixtures, ergonometric desk lamps, explosion-proof globes and other single-end access fixtures formerly requiring incandescent lamps.
In order to provide a wide range of sockets in large quantity and at low cost to meet expected demand, need for improvement in socket design for efficient, low cost manufacture has become apparent.
Presently, a socket for a compact fluorescent lamp is typically assembled in several steps from five or more molded plastic and stamped metal component parts. Furthermore, the metal elements are fabricated from two different kinds of metal stock. The plastic elements, which slide one within the other during assembly, must be molded to close tolerances, closer than are required for an adequate fit between socket and lamp base in actual use.
One example of this socket design is an Edwin Gaynor Company socket designed for seven and nine watt compact fluorescent lamps. The socket includes a housing enclosure, open at one end to accept a U-shaped insert having on a first pair of opposite sides, recessed upstanding terminal-embracing posts. The housing enclosure is molded in one piece with inboard vertical slots to accept the posts in a close sliding fit. The insert is also molded in one piece with the same precision and also includes, within the posts, multicontoured recesses to receive and hold a copper or phosphor bronze terminal strip pressed sideways into each post at its upper portion, and a tapered opening at its bottom to permit quick wire access to the terminal strip. A U-shaped clip which is stamped and formed from resilient steel, embraces the bottom of the insert and extends upward, around it, on the second pair of opposite sides. During manufacture, the terminals are pressed into the posts, the clip is forced over the bottom of the insert and the resulting sub-assembly is oriented and inserted slidingly down into the housing enclosure.
In another example, as described in U.S. Pat. No. 4,596,433 for a LAMPHOLDER HAVING INTERNAL COOLING PASSAGES, issued June 24, 1986 to Klaus Oesterheld et al, the four-part socket assembly includes a housing open at one end whereby a resilient steel U-shaped clip is pressed in from the front and is held grippingly in the housing by outwardly and upwardly directed stamped fingers which bear against the inner surface of the housing walls on opposite sides. At the bottom of the housing there are two openings for the stamped and shaped terminals which are pressed directly into the housing on each side, from the bottom.